Double star
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In observational astronomy, a double star or visual double is a pair of stars that appear close to each other as viewed from Earth, especially with the aid of optical telescopes.
The Hubble Telescope's 100,000th capture showing two stars that appear close together. The star on the right is a nearby Milky Way star while the star to the left is a quasar 9 billion light years away. This is an example of an optical double and is due to the quasar's immense luminosity.
Astronomers have mistakenly reported observations of a double star in place of J 900 and a faint star in the constellation of Gemini.
The color-contrastant binary Gamma Andromedae seen by a telescope
Albireo
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Albireo is a double star designated Beta Cygni. The International Astronomical Union uses the name "Albireo" specifically for the brightest star in the system. Although designated 'beta', it is fainte
Double star
…Winnecke 4 (Messier 40) Albireo A and Albireo B Kappa1 and Kappa2 Coronae Australis…
Albireo is the star in the head of the constellation of Cygnus (bottom).
Albireo A and B